Bizarre Intercom Problem

[RobHill]

Glad to hear the problem is solved. I am sure you are too. Thank you for taking the time to describe your actions to identify and fix the culprit areas.

I am curious about something. My understanding of squelch is that it prevents the passage of audio from the radio to the headset or speaker unless the received radio signal is above the squelch level. It sounds from the thread as though some noise, maybe above human audible range, was triggering the voice (noise) operated microphone in the headset, sometimes called Voice Operated Transmit (VOX).

Apparently your system has a control which can adjust the threshold at which the microphone starts passing an electrical signal representing the sound it is "hearing".

Is that correct? If yes, is the threshold control part of the headset apparatus or on the audio control panel?

Or is my understanding of VOX faulty?

Thank you.

[Andy Young]

Glad to hear the problem is solved. I am sure you are too. Thank you for taking the time to describe your actions to identify and fix the culprit areas.

I am curious about something. My understanding of squelch is that it prevents the passage of audio from the radio to the headset or speaker unless the received radio signal is above the squelch level. It sounds from the thread as though some noise, maybe above human audible range, was triggering the voice (noise) operated microphone in the headset, sometimes called Voice Operated Transmit (VOX).

Apparently your system has a control which can adjust the threshold at which the microphone starts passing an electrical signal representing the sound it is "hearing".

Is that correct? If yes, is the threshold control part of the headset apparatus or on the audio control panel?

Or is my understanding of VOX faulty?

Thank you.

There is a squelch adjustment on your radio that does as you describe; it adjusts the threshold level of incoming transmissions that are passed through to the headset (or the aircraft speaker). There is also a squelch adjustment on the intercom that adjusts the threshold level at which it will essentially "turn on" the microphone on your headset, so as to accept signals from the microphone and pass them on to the speakers on the headsets.
The setup for the latter case differs, depending on the equipment in your aircraft. Some have the intercom built into the radio, some have it built into the audio panel, some have it as a stand-alone piece of equipment. In some it is even portable. To add to that, some have adjustable squelch, via a knob, while others have automatic adjustment.

Hope that answers your question.

[RobHill]

Thanks for the info. Things are getting fancy.